Photographic-plate holder.



E. BRAUBURGER.

PHOTOGRAPHIC PLATE HOLDER.

APPLICATION FILED NOV. 13, 1912.

1 ,1 99,238. Patented Sept. 26, 1916.

Fig.1. h Fig.3.

UNITED STATES PATENT OFFICE.

ERNST BRAUBURGER, OF FRIEDENAU, GERMANY, ASSIGNQR TO THE FIRM OFOPTISCHE ANSTALT C. P. GOEBZ AKTIENGESELLSCHAFT, OF FRIEDENAU, NEARBERLIN, GERMANY.

PHOTOGRAPHIC-PLATE HOLDER.

Specification of Letters Patent.

Patented Sept. 26, 1916.

To all whom it may concern:

Be it known that I, ERNsT BRAUBU'RGER, a citizen of the German Empire,and resident of Fricdenau, near Berlin, Germany, have invented certainnew and useful Improvements in and Relating to Photographic- PlateHolders, of which the following is a specification.

My invention relates to a photographic plate holder especially for usein connection with photographic cameras for photogrammetrical,spectrographical and other solentific purposes where it is essentialthat the distance between the objective and the sensitive surface isabsolutely identical for a plurality of exposures made on photographicplates contained within different plate holders.

The invention is illustrated on the accompanying drawing in connectionwith a double plate holder.

Figure 1 shows an embodiment of the new plate holder from the back side,Fig. 2 a cross-section on lines 22 of Figs. 1 and 3, and Fig. 3 alongitudinal section through the plate holder on lines 33 of Figs. 1 and2.

The plate holder frames is designated a.

b is a dark slide adapted to control the exposing opening of the plateholder; 0, 0 are springs provided at both sides of the plate holderspace; (Z is a carrying frame for a plate 6, is a wedge shaped framemember of the carrying frame (Z provided at the top side of the exposingopening.

,9 are lateral flanges 0f the frame (Z which form guide-ways for plate 6within said carrying frame.

it are lateral ledges adapted to be inserted into suitable guide-ways ofa photographic camera for bringing the plate holder into position forexposing a sensitive plate contained therein.

The operation of the new plate holder is as follows: Assuming the plateholder containing a plate 6 and having its exposing opening closed bydark slide 6 is connected to a photographic camera and an exposure is tobe made, then the dark slide is pulled out so that the exposing openingis uncovered. Springs 0 push the frame cl with plate 6 toward theexposing opening till flanges g or the sensitive surface itself comeinto abutment with parts of the camera lying within the path of frame (Zwith plate 6. Thus the fixed abutment members of the camera control theposition of the sensitive surface during the exposure; therefore thisposition is independent from the dimensions of the plate holder and isalways the same in spite of eventual use of differently sized plateholders. Cameras designed for making exposures for photogrammetricpurposes are usually provided with adjustment or measuring members;these may advantageously be used as stop members for limiting theforward movement of the plate taking place when such cameras areconnected with the new plate holder and the dark slide of same isopened. After the exposure is made the carrying frame (Z with plate 6 isautomatically pushed back into the holder compartment on closing thedark slide 6 by the contact of the front edge of the dark slide with theinclined surface of the wedge shaped upper frame member That I claimis 1. A photographic plate holder provided with an exposure opening, andwith a dark slide insertible in said plate holder to cover said opening,means freely and unobstructedly movable into and out of said exposureopening and adapted to support a sensitive plate for exposure, and meansfor actuating said movable plate supporting means.

2. A photographic plate holder provided with an exposure opening andwith a dark slide insertible in said plate holder to cover said opening,means, freely and unobstructedly movable into and out of said exposureopening and adapted to support a sensitive plate for exposure, means forautomatically projecting said plate supporting means through saidopening when said dark slide is withdrawn, and means for automaticallyreturning said supporting means through said opening into said plateholder when said dark slide is returned to its closed position. 7

In testimony whereof I have signed this specification in the presence oftwo subscribmg witnesses.

ERNST BRAUBURGER. WVitnesses VVOLDEMAR HAUPT, HENRY HASPER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

' Washington, D. O.

